User's Manual
Moog Components Group • www.moog.com/components
system. The Model 918 Servo Actuator
provides the pitch roll-yaw functioning for
this system.
• Size: 11.30 x 4.59 x 6.53 inches
• Power: 115 VRMs, 400 Hz
• Weight: 11 lbs
• Command: ±10 VDC
• Position feedback: resolver
• High efciency steel gearing
• Rate feedback: brushless DC tachometer
• Fail-safe brake: optional
• Inertial loads: to 4200 lbs-in
2
• Scan Modes: 48, 91, 96, 153, 160, 320
 480 and 960 rpm
• Sector Mode : ±48°
• Bit test outputs 
•  Robust structural design
• MTBF: 5000 hrs
Model 918
Our military
qualied Model
918 Rotary Brushless
Stepper Actuator controls
the pitch-roll-yaw function of an antenna
system in conjunction with the Model 917
azimuth drives.
• Size: 4.06 x 2.50 x 4.35 inches
• Power: 20 VDC
• Weight: 2 lbs
• Command: ±10 VDC
• No-load speed: 300 rpm
• Fail-safe brake: none
• Inertial loads: 3 lb-in
2
• Position accuracy: ±0.5°
• Backlash: 30 arc-minutes
• MTBF: 5000 hrs
• Stroke: ±3600°
• Robust structural design
• High efciency steel gearing
Model 961 and 962
Our Model 961 Rotary Actuator in conjunction 
with  the  Model  962  Transconductance 
Amplier  may  be  used  for  the antenna’s 
azimuth and  elevation  rotary function, or 
similar high torque applications.
Model 971
Our  military  qualied  Model  971  Rotary, 
Brushless, Stepper 
Motor.  Limited 
Rotation Trim 
Actuator for the 
military helicopter.
• Size: 3.0 x 3.48 x 6.56 inches
• Power: 28 VDC
• Weight: 3.2 lbs
• Holding torque: 200 in-lbs
• Command: four phase stepper motor 
control from an external amplier
• Stroke: ±30°
• Step rate: 1 rpm
• Step size: 0.1°
• Load rate: 15 in-lbs @ 0.6 rpm
• Eddy current damper
• Backlash: 0.15°
• MTBF: 5000 hrs
Model 993
Our Model 
993 Rotary 
Servo Actuator 
provides mechanical 
valve control of the 
aircraft’s hydraulic ight control surfaces.
• Size: 4.10 inch diameter x 7.9 inches
• Power: 28 VDC
•  Power point: 200 in-lb @ 96 deg/sec
•  Weight: 7.4 lbs
•  Peak torque: 205 in-lb
•  Brushless motor with Hall sensor 
electronic commutation
• Brushless RVDT position transducer
•  Derived tach signal
•  BIT logic outputs
•  Robust structural design
•   Clutched output
•  High efciency spur gearing
•  Pulse width modulated motor power
•  Tach signal output
•  ±10 VDC input command signal to  
  position signal output
•   Torque output limit electronics
•  Position or rate servo operation
•  Low backlash
•  High reliability - 60,000 hour MTBF
•  No load speed: 110 deg/sec
•  Stroke: ±120°
• Size: 3.055 x 3.055 x 8.24 (961 only)
• Power point: 750 in-lb @ 30 rpm
• Weight: 13.6 lbs
• Peak torque: 1100 in-lbs
• Qualied design
• Rugged construction
• Brushless permanent magnet DC motor
• Broad operating temperature range
• E.M. brake with manual operation
• 150 VDC system
• ±10 VDC position command signal
• No load speed: 40 rpm
Model 965
The Model 965 Rotary 
Servo  Actuator is 
used  to  position  the 
control surfaces plus 
utility  applications  in 
unmanned air vehicles. 
This unit is designed to operate under the 
demanding  environmental  requirements 
seen worldwide.
• Size: 3.50 x 7.10 x 8.90 inches long from 
front of mounting ange to rear of housing
• Power: 28 VDC
• Rated Power Point: 2200 in lbs @ 35 
deg/sec 
• Weight: 10.7 lbs
• Peak torque: 2500 in lbs
• SMCO permanent magnet DC brush motor
• ±10 VDC analog input command
• Robust structural design
• Low endplay
• High efciency steel gearing
• Position output signal
• Electronic position and torque limiting
• Non-jamming mechanical stops
• Film position transducer
• Front ange mount
• Stroke: ±45º electrical stroke
• Bandwidth to 8 Hz
• No-load speed: 87 deg/sec
• MTBF: 5000 hr
Rotary Servo Actuators








